Open Radar

 
Summary:
If you attempt two-finger scrolling while clicking and dragging an object, a scroll action is queued. In applications (such as Logic), if you do the same while copying an object (alt+drag), a zoom is queued. There is no feedback for this, however, so a jarring scroll will occur when you complete your operation.

Steps to Reproduce:
1. Go to a directory in the finder with a lot of items.
2. Click and hold (and drag a little) on an item near the top.
3. Attempt to scroll while still holding the button down.
4. Release the mouse button.

Expected Results:
At step 3, I expect a scroll.
After step 4, having witnessed the results of step 3, I expect nothing to happen.

Actual Results:
At step 3, attempting to scroll does nothing.
After step 4, all the scroll operations I attempted in step 3 occur at once.

Notes:
This happens in most applications. I've noticed it in the Finder, Logic and Firefox, so I don't doubt it happens in a lot of other places too.

Perhaps it's just Propellerhead's Reason mistraining me, but I see no reason for scrolling during a drag to be impossible. Dragging an item to the edge of a pane to scroll the is a ridiculous, specific and slow thing to expect people to do. Lion's approach encourages two-finger scrolling wherever possible, and this is a really bizarre inconsistency.

Worse, if you're going to disallow such an action, there should certainly not be a delayed penalty for attempting the otherwise familiar method.